The prostaglandins are a group of hormone-like substances which may be viewed as derivatives of prostanoic acid. Several prostaglandins are found widely distributed in mammalian tissue and have been isolated from this source. These prostaglandins have been shown to possess a variety of biological properties such as bronchodilation and the ability to reduce gastric secretion.
The present invention concerns 9-dehydro-9-deoxy-PGD.sub.2 derivatives which, in addition, bear either a methyl, ethynyl, or phenyl substituent at the 9 position (using the prostanoic acid numbering system).